The study suggests that in total, around 57,000 patients a year are dying in NHS hospitals without being told that efforts to keep them alive have been stopped.

It also reveals that thousands of dying patients have been left to suffer in pain, with no attempt to keep them comfortable while drugs were administered.

Jeremy Hunt, the Health Secretary, last night described the disclosures from records held by 178 NHS hospitals as "totally unacceptable".

He said the failure to consult patients would now be examined by an independent inquiry, which will also look at payments made to hospitals for meeting targets to place people on the pathway.

Each year around 130,000 patients are placed on the pathway. The national audit by the Marie Curie Palliative Care Institute Liverpool and the Royal College of Physicians examined a representative sample of 7,058 deaths which occurred between April and June last year, at 178 NHS hospitals. Of these, X were on the pathway.

The new disclosures demonstrate just how routinely hospitals are placing patients on the pathway without informing them that steps which could hasten their death have been taken. The national audit found:

• In 44 per cent of cases when conscious patients were placed on the pathway, there was no record that the decision had been discussed with them.

• For 22 per cent of patients on the pathway, there was no evidence that comfort and safety had been maintained while medication was administered.

• One in three families of the dying never received a leaflet they should have been given to explain the process.

Critics of the pathway - which can involve the withdrawal of drugs, fluids and food, and the administration of powerful pain relief - say it is being used to hasten the deaths of the terminally-ill and elderly, in a form of "back-door euthanasia".

Other doctors, nurses and charities for the dying have come to the defence of the approach, which they say is intended to help ensure that people can die in dignity and comfort, instead of enduring invasive and painful treatment.

In recent months, there has been mounting concern over cases in which family members said they were not consulted or even told when food and fluids were withheld from their loved ones.

Earlier this month, Mr Hunt pledged to strengthen laws to protect patients, making it illegal to put anyone on the pathway - which leads to death in an average of 29 hours - without consulting them or their families.

It comes as the Government prepares to launch a new "vision for nursing" this week which will attempt to instill compassion in the profession, amid deepening concerns about the quality of care being provided on hospital wards.

Last night Mr Hunt said the evidence would be examined as part of an independent review of the practice, which will report back to him in the New Year.

He told The Sunday Telegraph: "It is totally unacceptable for people to be put on the pathway without consent where they are able to give it - that is why we are looking at what goes on in practice to make sure this doesn't happen."

Mr Hunt said he was concerned that families and patients were not being sufficiently informed, but suggested the approach to end-of-life care had been mischaracterised by some of its critics.

"We need to be much better at ensuring we are giving people dignity in their final few hours and the Liverpool Care Pathway has played a really important role in improving the standard of care in hospital, to hospice level," he said.

Earlier this month, the Department of Health began a three-month consultation on changes to the NHS constitution, which would give patients and their families a legal right to be consulted on all decisions about end-of-life care.

The rights will mean patients and relatives could sue if the requirements are not met, and doctors could be struck off if they fail to consult properly.

In a hard-hitting speech last week Mr Hunt expressed concern about the culture of the NHS, warning that too many patients were forced to experience "coldness, resentment, indifference" and "even contempt".

He warned that in the worst institutions a "normalisation of cruelty" had been fostered.

The family of Arthur Oszek, 86, say they did not find out he had been put on the Liverpool Care Pathway last year until he was left begging for a drink, having been taken off his drip.

After almost a day of discussion with medical staff, treatment was resumed, but it was too late, and Mr Oszek died within 24 hours last August.

Ann Murdoch, Mr Oszek's stepdaughter, said: "We asked the doctors why he was taken off his drip and we were told he was on the Liverpool Care Pathway. We did not even know what it was."

"There is no way that should have happened without asking us. We kicked up a fuss and demanded he be put back on his medication and eventually they agreed about 20 hours later."

NHS Ayrshire and Arran said they could not comment on individual cases, but discussed their assessments with patients and families wherever possible. On other occasions, patients placed on the pathway because doctors judged that they were nearing the end of their life went on to recover.

Patricia Greenwood, 82, was put on the pathway in August, after being admitted to Blackpool Victoria Hospital with heart problems, and then suffering a fall.

Doctors told her family that they had taken her off feeding tubes because she was not expected to last more than a couple of days.

After her son, Terry, 57, defied the hospital's orders and gave her sips of water through a straw, Mrs Greenwood, a former pub landlady, rallied, and doctors agreed to put her back on a drip.

She is now back at home and has made plans for a world cruise. The hospital trust said it had not received a complaint about her care.

A survey of 22,000 recently-bereaved Britons found relatives of those cared for in hospices rated the care far better than those whose loved ones spent their last months of life in hospital.

Less than half of families felt hospital nurses had always treated their relative with respect, compared with 80 per cent of those whose loved ones were treated in hospices.

One in six respondents said decisions were made about care which the patient would not have wanted.

Overall, health services in London were rated worst for quality of care, featuring most regularly in the bottom 20 per cent, as rated by the bereaved, while those in the South West scored most highly.